【作者】 陈慧新；

【导师】 余新晓；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2008， 硕士

【摘要】 本文主要研究北京山区密云水库流域常见树种的光合特性和蒸腾耗水特性,揭示不同树种的耗水特征,在此基础上结合抗旱造林技术,得出适宜北京山区的低耗水树种和最佳造林密度。针对密云水库流域现有的植被分布特点,选择22种乔灌木和2个典型林分(油松林和侧柏栎类混交林)作为研究对象,通过盆栽法和典型林分耗水试验,应用数学统计方法,分析了光合蒸腾耗水特征,得出如下结论:不同树种由于其本身的生物学特性,形成不同的生态适应性。在水分充足条件下,供试22个试验树种光合速率、蒸腾速率与水分利用率日变化曲线呈相似的变化趋势。乔木树种中,阔叶树种的光合、蒸腾速率高于针叶树种,平均水分利用率针叶树种大于阔叶树种。灌木树种中,阳性的蒸腾速率高于阴性树种;平均水分利用率是阴性灌木大于阳性灌木树种。乔灌木树种的蒸腾速率、光合速率和气孔导度日变化曲线呈相似的单峰或双峰曲线,阔叶乔木树种日最大蒸腾速率从大到小的顺序依次:臭椿>麻栎>槲树>刺槐>栓皮栎。日平均水分利用率从大到小的顺序依次:栓皮栎>麻栎>槲树>刺槐>臭椿。槲树水分利用率最高,臭椿的水分利用率最低。灌木树种日最大蒸腾速率从大到小的顺序依次:鼠李>黄栌>酸枣>孩儿拳头>荆条>火炬>花木蓝>雀儿舌头。分析了与环境因子的相关分析表明,侧柏和油松与气孔导度和光照强度为显著相关,建立多元线性回归分析模型:Y=a+bX1+cX2+dX3+eX4+fX5,相关系数很高。从树种间的耗水量比较发现,刺槐的蒸腾耗水量最大,其次是油松,侧柏、槲树、麻栎和栓皮栎的耗水量差距不大,耗水量排序为刺槐>麻栎>槲树>油松>栓皮栎>侧柏。本文正是在试验研究的基础上,通过对北京山区人工林优势树种光合蒸腾作用,耗水变化规律的研究,为密云水库集水区水源保护林的高效空间配置和稳定林分结构设计提供理论基础,也为相邻相近或同类地区的林业工程建设提供技术支撑。为在水分承载量的基础上,维持林地的土壤水分平衡,可以达到恢复森林植被、扩大森林资源、改善生态环境的目的。本文研究得出,年降水量660mm的北京密云水源保护林中油松、刺槐的造林密度宜在65~90株/亩。30年内基本上能够保证林木成活和成林的用水需要。更多还原

【Abstract】 This article mainly researches Photosynthetic and Transpiration of Dominant Tree Species in Miyun reservoir watershed in Mountain Area of Northern China .Reveal characteristics and rules of water consumption of different species. On the basic of the analytical results, combine drought-resistant afforestation technology; find the low consumption tree species and optimum planting density.Contraposing the existing vegetation of Miyun reservoir watershed, choosing 22 kinds of shrubs and two pieces of typical forest stand as research object, obtain following conclusion by pot experiment and experiment of typical forest stand, field and experimental research, applying statistical method to analyze photosynthetic and transpiration. The main conclusion is as follows:Because of biological characteristics of different tree species, form different Ecological Adaptability. At water enough condition, 22 tree species of the young plant used in the experiment whose tendency of transpiration rate, photosynthetic rate and the diurnal changes of water use efficiency are similar. The transpiration rate of arbor trees is higher than Coniferous Trees’, but in the average efficiency of using water, Coniferous Trees is greatly higher than arbor trees’. The transpiration rate of positive shrub species is greatly higher than negative shrubs species’, but in the average efficiency of using water, negative shrubs species is greatly higher than Coniferous Trees’.The water consumption of tree increased with increasing stand density,thus,the soil moisture decreased correspondingly.The bare soil had strong evaporation and its watercontent was lower than woodland.Therefore,the reasonable spatial structure and stand density inforestation would be beneficial to increase and maintain soil moisture.更多还原